Sensitive relay



. July 21, 1959 F. E. WOOD 2,896,048

sausrrxvxz RELAY Filed July 10. 1957 -FIG.2

I ill 3/3312 3/7 3I6 322 INVENTOR. FREDR/C E. WOOD ATTX United States Patent SENSITIVE RELAY Fredric E. Wood, McHenry, 11]., assignor to General Telephone Laboratories, incorporated, Chicago, 111., a corporation of Delaware Application July 10, 1957, Serial No. 671,010 2 Claims. (Cl. 200-104) This invention relates to electromagnetic relays and more particularly to those requiring sensitive adjustment.

It is an object of the present invention to provide a new and more eflicient method of obtaining the required contact pressure and contact separation of a sensitive relay.

A feature of the invention is the provision of a relay having fast-to-release characteristics in addition to sensitive adjustment.

A further feature of the relay as set out herein is that the relay contact springs will open on deenergization of the relay coil with a minimum of contact vibration.

The invention relates to relays of the type shown in U.S. Patent 2,401,213, issued to F. E. Wood on May 28, 1946.

Referring to the drawings, Fig. 1 shows a top view of the relay. Fig. 2 shows a side view and Fig. 3, a view of the other side of the relay.

The relay structure in general as regards the coil, armature and heelpiece mechanisms is generally the same as that shown in the cited Wood patent. In the coil as used herein a special coil with a small diameter nickel iron core having an enlarged pole face 114 is incorporated to further increase the sensitivity of the relay.

The contact springs 226 and 227 of Fig. 2 and 326 and 327 of Fig. 3 are of the same shape and design shown in the cited Wood patent. Springs 226 and 227 form a make-combination and comprise what will be considered as the right spring pileup under washer 222. Springs 326 and 327 form a break-combination and are included under washer 322 into the left pileup.

The right pileups consists of a number of insulators 120, movable contact spring 227, movable adjusting spring 217, another insulator 120, stationary contact spring 226, insulators 120, stationary adjusting spring 216, insulator 120 and washer 222. The springs of the right pileup as mentioned, form a make-combination.

The left pileup provides a break-combination formed by insulators 120, back contact spring 326, an insulator 120, movable spring 327, adjusting spring 317 for the movable spring 327, insulators 120, adjusting spring 316 for the back contact spring 326, insulator 120 and washer 332.

The sensitive adjustment for both pileups is controlled from the U shaped bracket 111 which is mounted to heelpiece 116 through support bushing 129 which has knurled top and bottom surfaces to provide firm contacting surfaces. The bracket has tapped holes in each arm of the U to receive the adjustment screws 211, 213, 311 and 313. The screws are mounted in parallel alignment through the tapped holes so that each of the screws is adjacent one of the adjusting springs. Each of these screws has a phenolic insulator 212, 214, 312 and 314 set into its spring contacting end and a slot at its further end.

On a standard relay, contact pressure is obtained by deflecting the movable spring. Since the spring is long and is mounted in cantilever fashion, it cannot be ac- 2,896,048 Patented July 21, 1959 curately positioned by this manual adjustment. Also, a considerable portion of the relay stroke is wasted in deflecting the spring to obtain the required contact pressure.

Micrometer screw 211 acts in combination with nickelsilver tension spring 213 to govern the restoring force of movable contact spring 227. Advance of screw 211 forces the tension spring toward the heelpiece. This force tends to bow contact spring 227 toward the heelpiece and increase the restorative force on contact spring 227. The micrometer adjusting screw 211 is insulated from the tension spring 217 by the phenolic tip 212 embedded into the leading end of screw 211.

Screw 213 through its phenolic tip 214 contacts brass stop spring 216. This stop spring is made of a heavier gauge metal than are the remaining springs. This screw and stop spring adjustment regulate the contact gap between the stationary spring and the movable spring. Advancing screw 213 forces the free end of stop spring 216 against the stationary make spring 226 reducing the contact gap. The stop spring 216 also has a secondary function. Near its free end, the stop spring 216 rests against the stationary spring 226 at a line of contact about a quarter of an inch inward of the spring contacts. The armature spring then has only this quarter of an inch of free length which is free to flex during relay operation and a large amount of contact pressure can therefore be generated in the spring combination. When the armature spring 227 is deflected, it contacts make spring 226 and forces the outward end of the make spring against the stop spring. In this manner a high contact pressure may be developed. Further, the stop spring may be adjusted so that the fully operated position of the relay is achieved with the armature not fully against the coil core 114. An adjustment of this type would provide a quick-to-release relay.

The contacts of Fig. 3 constitute a break-combination. Tension spring 317 acts against the armature spring 327 to provide the spring tension and contact pressure. This tension spring is made of light gauge nickel silver material. Brass stop spring 316 varies the relative position of back contact spring 326 to vary the contact gap. Further, due to the fact that the contact springs although mounted in the pileups as cantilever springs are supported along their free lengths by the stop springs, vibration of the contact springs can occur only along the exposed portion of their length. Thus vibratory contacting will be stopped rapidly and the vibrations will be of small amplitude.

By the use of these accurate adjusting screws, each contact spring of the relay is capable of being adjusted to close tolerances.

What is claimed is:

1. In a relay having a heelpiece, an armature pivotally mounted to one end of said heelpiece, a plurality of contact springs mounted to said other end of said heelpiece, two of said springs combinedly forming a make combination including a stationary spring and a movable spring, said movable spring actuated by pivoting of said armature to impinge against said stationary spring, a first adjusting spring acting on said movable spring for increasing or decreasing the tension in said movable spring, said first adjusting spring formed of a light gauge spring material, a second adjusting spring acting on said stationary spring for changing the contact separation distance between said springs, said second adjusting spring formed of a rigid spring material to arrest the momentum imparted to said stationary spring by impingement thereagainst by said movable spring to thereby damp out vibrations of said stationary spring, a U-shaped bracket aifixed transversely to said heelpiece, individual control means advanceably and retractably mounted through the legs of said U shaped bracket, each of said control means aligned in parallel relationship and controllably contacting individually said first and second adjusting springs.

2. In a relay having a make-combination and a breakcombination, each of said combinations comprising a movable spring and a stationary spring, an armature arm for actuating each of said movable springs, the movable spring of said make-combination moved toward the stationary spring of said make-combination on actuation of the armature arm, the movable spring of said breakcombination moved away from said stationary spring on actuation of the armature, a tension spring tactually adjacent each of said movable springs for adjusting the tension thereof, a cantilever spacing spring tactually adjacent each of said stationary springs, the spacing spring adjacent the stationary spring of said make-combination adjustably maintaining the separation distance between the springs of said make-combination in the normal state, the spacing spring adjacent the stationary spring of said break-combination adjustably maintaining the separation between the springs of said break-combination as actuated by said armature, both said spacing springs of rigid construction to damp out excess motion of said stationary spring, an individual lead screw advanceably mounted longitudinally to each of said tension and spacing springs, all said lead screws commonly forming a single plane, each of said tension springs deformable on advance of the individual lead screw to increase the tension on the adjacent movable spring, said lead screws advanceable from the free end of all said springs, each of said spacing springs pivotable at the cantilever mounting on advance of the individual lead screws, said make-combination spacing spring pivotable to decrease the separation between the springs of the make-combination, said breakcombination spacing spring pivotable to increase the separation gap of said break-combination springs in the actuated position.

References Cited in the file of this patent UNiTED STATES PATENTS 1,108,320 Berdon Aug. 25, 1914 1,121,897 Craft Dec. 22, 1914 1,496,783 Mills June 10, 1924 2,075,499 Buch et al. Mar. 30, 1937 2,399,123 Jordan Apr. 23, 1946 2,598,519 Durbin May 27, 1952 2,741,675 Chase et al Apr. 10, 1956 

